Prehospital Point of Care Testing for the Early Detection of Shock and Prediction of Lifesaving Interventions

Samuel M Galvagno Jr, Robert A Sikorski, Douglas J Floccare, Peter Rock, Michael A Mazzeffi, Joseph J DuBose, Thomas M Scalea, Catriona Miller, Justin E Richards, James V O'Connor, Colin F Mackenzie, Peter Hu

Shock 2020 May 21; Online ahead of print 

Introduction: Early diagnosis and treatment are essential for enhancing outcomes for the traumatically injured. In this prospective prehospital observational study, we hypothesized that a variety of laboratory results measured in the prehospital environment would predict both the presence of early shock and the need for LSIs for adult patients with traumatic injuries.

Methods: Adult trauma patients flown by a helicopter emergency medical service were prospectively enrolled. Using an i-STAT® portable analyzer, data from sixteen laboratory tests were collected. Vital signs data were also collected. Outcomes of interest included detection of shock, mortality, and requirement for lifesaving interventions (LSIs). Logistic regression, including a Bayesian analysis, was performed.

Results: Among 300 patients screened for enrollment, 261 had complete laboratory data for analysis. The majority of patients were male (75%) with blunt trauma (91.2%). The median injury severity score was 29 (IQR, 25-75) and overall mortality was 4.6%. A total of 170 LSIs were performed. The median lactate for patients who required a LSI was 4.1 (IQR, 3-5.4). The odds of requiring a LSI within the first hour of admission to the trauma center was highly associated with increases in lactate and glucose. A lactate level > 4 mmol/L was statistically associated with greater sensitivity and specificity for predicting the need for a LSI compared to shock index.

Conclusions: In this prospective observational trial, lactate outperformed static vital signs, including shock index, for detecting shock and predicting the need for LSIs. A lactate level > 4 mmol/L was found to be highly associated with the need for LSIs.